I'm thinking either it came from lessons learned after the disproportionate police response to BLM so things are toned down
It appears that this is one reason for the muted response to the storming of the US Capitol. A Washington Post article describes how "Pentagon leaders were still smarting from criticism of their role in the Trump administration’s outsized and militarized response to protests in the capital following the police killing of George Floyd in Minneapolis."
The article says that top Pentagon officials stated earlier this week that law enforcement officers would be deployed away from the Capitol to avoid any scenes like those of last summer:
With those events in mind, top defense officials specifically ensured that the 340 members of the D.C. Guard whose activation were requested this week by D.C. Mayor Muriel E. Bowser would stay away from the Capitol to avoid the poor optics of uniformed military personnel and Humvees flanking civilian protesters.
One senior U.S. official told The Washington Post on Tuesday, ahead of the demonstrations, that at the Pentagon, “everyone has got a lot of scar tissue and a lot of PTSD from the domestic unrest of the summer” and didn’t want a repeat. The official added, “We’ve learned our lessons and will be absolutely nowhere near the Capitol Building.”
In addition, it seems the Capitol Police had only prepared for peaceful protesting and did not anticipate the violence that occurred, as described in a Vox article:
But despite clear warning signs from Trump and his supporters — and the fact that city officials were on high alert — Capitol Police did not prepare for the size or violence of the crowd. Relaying conversations he’d had with police officials, Rep. Ryan told reporters the threat assessment done by law enforcement seriously underestimated the potential threat.
“Initially, it was that there wasn’t going to be any kind of violence anticipated,” Ryan said. “First Amendment protests, pretty vanilla, maybe some dust-ups ... but absolutely nothing like this.”
Police set up only low barriers around the perimeter of the building and were wearing ordinary uniforms instead of riot gear, the Post noted.